Kim Deuk-Pal is a 47 year old gangster and he is the #2 guy in his gang. He doesn’t have an educational background due to his poor parents, but he has a dream of attending a university. He has been studying to achieve his dream, but it’s not easy. One day, Kim Deuk-Pal sees a young man Song Yi-Heon about to kill himself. At that time, Kim Deuk-Pal’s spirit possesses the body of the suicidal 19 year old high school student. Kim Deuk-Pal soon learns that Song Yi-Heon is a victim of bullying, which has caused him to want to take his own life.
Now, Kim Deuk-Pal in the body of Song Yi-Heon, takes on the bullies to punish them and becomes friends with classmate Choi Se-Kyung. Choi Se-Kyung is a model student who appears to be in a perfect situation, but he suffers from domestic violence at home by his father.